Ernest, thanks for your clarification. thanks Gang
>From: [EMAIL PROTECTED] >Reply-To: [EMAIL PROTECTED] >To: [EMAIL PROTECTED] >Subject: Re: JESS: Re: Rules Transformed From XML >Date: Wed, 31 Jul 2002 14:06:05 -0700 (PDT) > >I think Gang Liu wrote: > > hi, all > > I got a question of multiple rules and multiple facts. Please help me >out. > > > > Two scenarios: > > 1. We have 2 facts in memory and they can fire one rule both. Are 2 >facts > > triggered sequencially? If RHS of that rule takes 5 ms to execute, the >time > > to trigger 2 facts will be at least 10 ms? Are there some ways of >triggering > > 2 facts in parallel? > > > >I'm really not sure what you're using the word "trigger" to mean here, >but I'm pretty sure the answer is "no." Things in Jess happen >sequentially, in a very controlled order. There has been plenty of >research on parallel production systems, and on parallel Rete >implementatons, even. In most practical systems, though, there are too >many join points for parallelization to do much good. Furthermore, the >amount of work needed to fire any given rule is different than the >amount needed for other rules, so simple parallelizations tend not to >have any benefit at all (recall Amdahl's law.) And of course, there's >no way to create a parallel implementation that runs as fast on a >single processor as an intrinsically uniprocessor version does -- >threads add overhead. > > > 2.We have 1 fact and it can fire 2 rules. Are 2 rules fired in seqence? > > Suppose RHS of the first fired rule takes 5 ms to execute, the second >rule > > has to wait for 5 ms to fire? > >Yes, rules fire one at a time, in a very specific order, as controlled >by salience and by the active Strategy object. > > > > > It seems that the questions are related to performance and thread-safe. > >Indeed. > > >--------------------------------------------------------- >Ernest Friedman-Hill >Distributed Systems Research Phone: (925) 294-2154 >Sandia National Labs FAX: (925) 294-2234 >Org. 8920, MS 9012 [EMAIL PROTECTED] >PO Box 969 http://herzberg.ca.sandia.gov >Livermore, CA 94550 > >-------------------------------------------------------------------- >To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' >in the BODY of a message to [EMAIL PROTECTED], NOT to the list >(use your own address!) List problems? Notify [EMAIL PROTECTED] >-------------------------------------------------------------------- _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED] --------------------------------------------------------------------
